Trifolium microdon (thimble clover)

Plate 1 figs. a–h · 8 separate observations

Trifolium microdon, photographed by James H. Thomas — fig. a James H. Thomas, CC BY 4.0 / 2022-05-08 / obs. 196154841

Trifolium microdon, photographed by Ken-ichi Ueda — fig. b Ken-ichi Ueda, CC BY 4.0 / obs. 195821856

Trifolium microdon, photographed by Spencer Quayle — fig. c Spencer Quayle, CC0 1.0 / obs. 193389584

Trifolium microdon, photographed by John Brew — fig. e John Brew, CC BY 4.0 / obs. 72857337

Trifolium microdon, photographed by Scott Loarie — fig. f Scott Loarie, CC0 1.0 / obs. 7809056

Trifolium microdon, photographed by Dee Shea Himes — fig. g Dee Shea Himes, CC BY 4.0 / obs. 185265322

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 7 botanical countries

Native distribution of Trifolium microdon, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.

Region	TDWG code	Continent
British Columbia	BRC	NORTHERN AMERICA
California	CAL
Idaho	IDA
Mexico Northwest	MXN
Oregon	ORE
Washington	WAS
Chile Central	CLC	SOUTHERN AMERICA

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 320 in flower of 347 examined

96%

94%

91%

71%

Proportion of examined Trifolium microdon in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	0	too few examined
Feb	0	1	too few examined
Mar	24	25	96%	80% to 99%
Apr	222	237	94%	90% to 96%
May	69	76	91%	82% to 95%
Jun	5	7	71%	36% to 92%
Jul	0	0	too few examined
Aug	0	0	too few examined
Sep	0	0	too few examined
Oct	0	0	too few examined
Nov	0	0	too few examined
Dec	0	1	too few examined

Peak flowering in Mar. Each bar is the share of Trifolium microdon observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 320 of 347 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 8 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Also published as 5 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

Trifolium lechleri Phil.
Trifolium microdon var. microdon
Trifolium microdon var. pilosum Eastw.
Trifolium tricuspidatum Bertero ex Steud.
Trifolium tricuspidntum Bertero ex Steud.

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.